WHAT HAPPENED: Facebook acknowledged Monday that 10 of its most popular "apps" transmitted information about its users to advertisers and data-gathering firms after a Wall Street Journal article pointed this out.
HOW? The apps, in most cases inadvertently, leaked users' unique Facebook IDs, which could then be used to find out users' names and any other information they made public on the site. Private information was not affected.
WHY IT MATTERS: Some privacy advocates say this shows Facebook can't enforce its own policies and commitments to privacy. Others called the issue overblown.